Git-Support: Improved the show buffer.

- When ':GitShow' is used to show blobs, it opens an appropriately named
  buffer and tries to detect the filetype automatically.
- Added syntax highlighting for annotated tags.
- Improved 's:StandardRun'.
- Documentation.
Git-Support: Running Git in xterm.

- Added :GitTerm.
- Added actions "add/checkout/reset --patch" in status buffer.
- Documentation.
Project: Project management.

- Removed script 'plugin/make.vim'.
- TODO list.
- Minor changes.
Merge branch 'gitsupport-dev'

- Updated the documentation.

Conflicts:
	doc/gitsupport.txt
	git-support/README.gitsupport
	plugin/git-support.vim